Keratoconus is a condition in which the normal clear and dome-shaped cornea becomes thin and bulges outward to form a cone shape. The cornea plays an important role in refracting and focusing rays of light for clear vision; hence, an altered shape disrupts the function and distorts normal vision. Keratoconus usually affects both eyes and can either develop suddenly or progress slowly over several years. It can manifest anytime; from childhood up to the age of about 30 years.
The signs and symptoms of keratoconus vary with the progression of the disease. Early symptoms include blurring of vision. Halos (rings seen around lights), night vision problems and glare may develop over time. You may also experience sudden clouding of vision.
When you present with any of these symptoms, your doctor will review your medical history, conduct an eye examination, and order a few diagnostic tests to measure the corneal curve to evaluate the projection and shape of your eyes.
Your doctor may suggest appropriate treatment options based on the severity and progression of the keratoconus.
Treatment strategies for keratoconus include:
Contact lenses are the most effective form of treatment for most cases of keratoconus. Early stages of the disease with blurred or distorted vision can be corrected with soft contact lenses. Progressing keratoconus can be treated with rigid gas permeable contact lenses. If you cannot tolerate hard contact lenses, your doctor may prescribe piggyback lenses (hard lens on top of a soft one) or hybrid lenses (rigid centre with outer soft ring). Advanced keratoconus and irregular changes in the cornea can be corrected with scleral contact lenses that rest on the white part of your eye (unlike other lenses) and cover the cornea without coming in contact with it.
Collagen Cross Linking
Collagen cross linking is an emerging treatment option for keratoconus. It involves applying vitamin drops to the cornea and exposing it to ultraviolet A (UVA) rays. This therapy prevents further thinning or bulging and strengthens the cornea.
Lamellar transplant can treat scarring or excessive thinning of the cornea. Lamellar transplant involves replacing only a section of the cornea’s tissue with a donor graft tissue instead of the whole cornea. You will have to wear contact lenses for about one year, during recovery. You will regain your full vision several years after the surgery.
Implantable Collamer Lens
Implantable collamer lens is a biocompatible soft lens that can be permanently implanted into your eye. During the procedure, your doctor will inject the collamer lens into your eye through a micro opening. The lens will unfold, and you will experience an immediate improvement in the quality of vision.
Intrastromal rings are also called as intracorneal ring segments or corneal inserts. Two tiny, crescent-shaped, clear plastic inserts will be inserted into your cornea to support the shape, flatten the cone and improve vision. This technique can slow the progression of keratoconus and restore the cornea’s shape to almost normal. This is a temporary measure as after the corneal shape is achieved, the inserts can be removed.
Keratoconus results in a rare complication called corneal hydrops. Hydrops occurs when the inner corneal layer (endothelium) ruptures and fills with fluid. This results in cloudiness and swelling of the cornea. Hydrops can be managed by instilling antibiotic, hypertonic saline drops or steroidal drops to prevent infection, relieve pain and discomfort. In time, the endothelial pump cells will remove the fluid from the cornea.